No, they haven't. If it had been in the interest of the Soviets to remain in Afganistan, or ours today, they would still be there. There is such a thing as giving up and going home without ever being defeated on the battlefield. Besides, someone is "sponsoring" them. When the Soviets were in Afganistan, we were the sponsors. Who's doing the sponsoring now?

Also, a militia does not necessarily fight a guerilla war and a guerilla war is not necessarily fought by a militia.